Ubuntu 11.10 Bug #862355 compiz crashed

compiz crashed with SIGSEGV in PrivateWindow::addWindowStackChanges()

just logged in

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: unity 4.18.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-11.18-aggressive 3.0.4-PICCHIARELLI
Uname: Linux 3.0.4picchiarelli+ x86_64
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu2
Architecture: amd64
CrashCounter: 1
Date: Thu Sep 29 14:39:33 2011
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
ProcCmdline: compiz
SegvAnalysis:
 Segfault happened at: 0x43f766 <_ZN13PrivateWindow21addWindowStackChangesEP14XWindowChangesP10CompWindow+38>: mov 0x68(%rdx),%rdi
 PC (0x0043f766) ok
 source "0x68(%rdx)" (0x00000068) not located in a known VMA region (needed readable region)!
 destination "%rdi" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: unity
StacktraceTop:
 PrivateWindow::addWindowStackChanges(XWindowChanges*, CompWindow*) ()
 CompWindow::lower() ()
 CompScreen::handleEvent(_XEvent*) ()
 PrivateCompositeScreen::handleEvent(_XEvent*) () from /usr/lib/compiz/libcomposite.so
 CompScreen::handleEvent(_XEvent*) ()
Title: compiz crashed with SIGSEGV in PrivateWindow::addWindowStackChanges()
UpgradeStatus: Upgraded to oneiric on 2011-09-28 (1 days ago)
UserGroups: adm admin cdrom dialout fax floppy fuse lpadmin netdev plugdev sambashare vboxusers